753results about "Polyphase network asymmetry reduction" patented technology

Embodiments of this invention discloses a split-phase output power adjustment system, adjustment method, and storage medium in a low voltage transformer area. The system includes adjustment power supplies, split-phase power adjustment modules, sub-controllers, a main controller. The adjustment power supplies connected to the split-phase power adjustment modules, and total power P of the adjustment power supplies complying with a relationship as follows: P=Pt=PG1+PG2+ . . . . PGn; wherein Pt is power required to comply with three-phase current unbalance adjustment of a distribution transformer, PG1, PG2, . . . PGn is power generated by each of the adjustment power supplies to compensate three-phase current unbalance in a transformer area; wherein the split-phase power adjustment modules are connected to lines of three phases A, B, and C and a neutral line N in the transformer area; wherein the sub-controllers are connected to the adjustment power supplies, and the sub-controllers communicate with the main controller to control power generated by each of the adjustment power supplies, so as to compensate the unbalanced three-phase current in the transformer area. Coordinated adjustment of multiple distributed power supplies realizes precise control of three-phase imbalance in the transformer area, which reduces line loss and improves power quality.

The invention relates to the technical field of power generation, power transformation or power distribution, and discloses a control method for preventing overload of an energy storage system transformer, which comprises the following steps: monitoring the three-phase total power and the power of each phase of a power grid side ammeter in real time, and calculating the three-phase unbalance degree based on the three-phase total power when the three-phase unbalance phenomenon occurs; when the three-phase unbalance degree is greater than a preset unbalance degree threshold value, dynamically adjusting the charging power of the energy storage converter according to a starting threshold value, a charging limiting threshold value and a charging forbidding threshold value by adopting a multi-threshold value dynamic adjustment mechanism; the phase with the maximum deviation between the power of each phase and the average power of the three phases is calculated as an overload phase, load reduction is performed on the overload phase based on a load increasing and decreasing strategy, load increasing is performed on a non-overload phase, and the adjusted three-phase power is obtained; a power distribution instruction is calculated in real time in combination with a dynamic response mechanism, and the three-phase unbalance degree does not exceed a safety threshold value in cooperation with total power control. The problems of easy overload, three-phase imbalance and slow response of a transformer in the prior art are solved, and the purposes of accurate load control, high system stability and high response speed are achieved.

The invention discloses a neutral-point potential balancing method and device for a three-level converter suitable for an unbalanced load, and belongs to the technical field of three-level converter control, and the method comprises the steps: 1, carrying out the positive and negative sequence separation of a sampling signal, and achieving the output of a three-phase balanced voltage; step 2, calculating an ideal zero-sequence component needing to be added in the modulated wave; step 3, analyzing the adjustment capability of adding the ideal zero-sequence component, and if the adjustment capability is satisfied, executing step 4; if not, skipping to step 7; 4, correcting a modulation wave symbol in the ideal zero-sequence component; 5, designing a potential regulator of the zero-sequence voltage based on the corrected modulation wave symbol; 6, performing amplitude limiting on the sum of the zero-sequence component generated by the potential regulator and the ideal zero-sequence component; step 7, carrying out midpoint balance by using an external balance circuit; and the three-level converter stops running, and the process is ended. According to the invention, neutral-point potential balance of the three-level converter is realized by adding the zero-sequence component in modulation.

The invention discloses a current prediction control method and system for an in-phase power supply device based on error differentiation. The method comprises the steps of collecting input voltage, input current and reference current data of the in-phase power supply device; establishing a current control system prediction data model, and optimizing and updating a pseudo-partial derivative matrix of the current control system prediction data model; designing a model-free self-adaptive predictive control scheme based on error differentiation, and optimizing and updating an error control gain matrix of the model-free self-adaptive predictive control scheme; processing the control input signal, and generating an on-off signal for controlling the in-phase power supply device after PWM (Pulse Width Modulation) modulation until the control task is finished; the control method and system provided by the invention are not only suitable for current control of the in-phase power supply device, reduce the modeling difficulty and improve the control precision, but also have the application prospect of being popularized to other single-input single-output systems.

The invention provides an impedance scanning device based on network side voltage dynamic compensation under a three-phase voltage imbalance working condition, and relates to the technical field of new energy station power electronic converter topology and control, the device comprises a three-phase rectifier, a direct current bus capacitor, an inverter, a voltage compensation device, a frequency sweeping device, a circuit breaker and a series transformer part, the three-phase rectifier is connected in series with inverters of the voltage compensation device and the frequency sweep device, a secondary side of a series transformer of the voltage compensation device is connected in series with a network side, a secondary side of a series transformer of the frequency sweep device is connected in series with a grid-connected point, and a primary side of the series transformer is connected to the inverters and is coupled to a secondary side of the series transformer; according to the device, the power grid side voltage is rectified through the voltage compensation unit and is compensated to the grid side after being subjected to single-stage inversion transformation, voltage compensation is achieved through the energy of a power grid when the voltage is unbalanced, and an external energy source or an interference source does not need to be introduced. After compensation, the accuracy of the frequency sweeping result is obviously improved.

The invention discloses a three-phase imbalance compensation method and system based on negative sequence current and a medium, and relates to the technical field related to power imbalance compensation, and the method comprises the steps: executing the three-phase current, voltage and reactive power data collection of a power distribution network, and carrying out the three-phase imbalance recognition through negative sequence current analysis; carrying out additional acquisition of a load mode and environment data on the power distribution network; taking the data acquisition result and the additional data set as input data to execute negative-sequence current change trend prediction; a double-layer compensation device is configured for cooperative control optimization; power distribution network balance compensation is executed through a time sequence compensation strategy, and time sequence window feedback is established; and carrying out adaptive strategy correction. The technical problems that in the prior art, a three-phase imbalance compensation strategy lacks perspectiveness and self-adaptive capacity and cannot cope with a dynamically-changing power grid scene, and consequently compensation precision and stability are poor are solved, and the technical effects that perspectiveness and predictive compensation is achieved, and three-phase imbalance compensation precision and stability are improved are achieved.

The invention discloses an intelligent commutation type three-phase imbalance dynamic treatment method for a power distribution network, relates to the technical field of power distribution network treatment, and aims to solve the problem of poor treatment effect of three-phase imbalance. By using the data mining and analysis technology, not only can the cost minimization path be calculated according to the current state, but also the future change can be pre-judged in combination with the load dynamic trend, so that the formulated switching strategy is more prospective and accurate, the generated high-dimensional mapping vector fuses the node characteristics and the neighbor node characteristics, and the switching efficiency is improved. By combining the use of a nonlinear activation function, the model can adaptively learn a load change rule, sensor equipment integrates various sensors and chips, has the functions of environment monitoring, power management and the like, and is matched with structural components to ensure the reliable operation of the device, reduce the operation and maintenance cost and difficulty and prolong the service life of the equipment.

The invention provides a three-phase imbalance treatment method, device, system, equipment, medium and product, an operation optimization model is adopted, the operation optimization model relates to commutation soft switching constraints and reactive compensation constraints, and a solution for indicating actions of a reactive compensation device and a commutation soft switching is calculated by minimizing an objective function of the operation optimization model. Therefore, three-phase imbalance treatment is carried out through cooperation of the reactive power compensation device and the phase-change soft switch. Due to the addition of the commutation soft switch, the three-phase imbalance treatment response speed is greatly increased; based on the algorithm processing, the topology and commutation soft switch replaces a traditional interconnection switch to be connected between the two transformer areas of the power distribution network, so that interconnection and mutual assistance between the transformer areas can be considered in three-phase imbalance treatment; moreover, the key voltage treatment target of voltage deviation is considered in the operation optimization model, so that the voltage of the power distribution network does not exceed the allowable range of the national standard in a high-permeability distributed power supply scene.

The invention discloses a power maximization output-oriented multi-target double-sequence current injection method under a three-phase imbalance fault, and the method comprises the following steps: S1, obtaining a three-phase voltage # imgabs0 # and a current # imgabs1 # of a PCC point after a fault steady state, and correspondingly obtaining a positive and negative sequence voltage # imgabs2 # and a current # imgabs3 # of the PCC point under a dq coordinate system; s2, according to the # imgabs 4 # and the # imgabs 5 #, calculating to obtain positive and negative sequence voltage # imgabs 6 # and phase angle difference # imgabs 7 # of the power grid in the current fault scene; s3, according to # imgabs8 # and # imgabs9 #, finding out positive and negative sequence current reference values of a dq axis in a 3-D lookup table; and S4, generating an inverter modulation signal through positive and negative sequence separation control according to the found dq-axis positive and negative sequence current reference values.

The invention provides a power distribution network three-phase unbalanced power flow rapid calculation method, system and device and a medium, and the method comprises the steps: building a voltage correction equation set according to the voltage data of each node in the branch data of a power distribution network; solving the voltage correction equation set by using a parallel computing method to obtain a correction value of the voltage data; carrying out load flow calculation on the power distribution network based on the convergence condition of the corrected value of the voltage data; according to the method, the voltage correction equation set established according to the voltage data of each node in the branch data of the power distribution network is solved through the parallel computing technology to realize correction of the voltage data, and the convergence of the correction value of the voltage data is judged, so that the calculation accuracy of unbalanced load flow calculation of the power distribution network is improved; and rapid solving of the complex power distribution network power flow is realized.

The invention relates to a three-phase imbalance treatment method and a micro-energy regulator, and belongs to the technical field of power supply systems. The method comprises the steps that when a three-phase imbalance phenomenon occurs, the three-phase imbalance degree is obtained according to the maximum power deviation between phases and the total power of the three phases; when the three-phase unbalance degree is greater than a preset unbalance degree, calculating the single-phase power deviation of each phase according to the three-phase average power and the single-phase power of each phase; comparing the three-phase total power with a preset transformer area load rate, and when the three-phase total power is greater than the preset transformer area load rate, storing energy and discharging; if yes, the single-phase power deviation needs to be updated according to corresponding design requirements; for energy storage, the total discharge power or the total power absorption power of each phase is determined according to the updated single-phase power deviation, proportional gain and integral gain; and discharging or absorbing electricity for each phase until the total discharging power or the total electricity absorbing power of each phase is met. According to the invention, the phenomenon of heavy load or return of the transformer area can be reduced.

The invention discloses a voltage balancing device of a 10KV three-element combined mutual inductor and a using method of the voltage balancing device, and relates to the technical field of mutual inductors. The voltage balancing device of the 10KV three-element combined mutual inductor comprises a first mutual inductor shell, the voltage balancing device comprises a second mutual inductor shell, a voltage mutual inductor is installed in the first mutual inductor shell, and a current mutual inductor is installed in the second mutual inductor shell. The front end of the first mutual inductor shell is fixedly connected with a mutual inductor junction box, a voltage stabilizer is installed outside the first mutual inductor shell, and by means of Y-shaped connection of a secondary winding of the voltage mutual inductor and use of a circuit breaker and the voltage stabilizer, voltage balance of the voltage mutual inductor is facilitated; the Y-shaped connection can guarantee three-phase balance while providing a stable power supply, has an effect of absorbing harmonic waves, improves the power supply efficiency, avoids equipment damage caused by overload, and guarantees good operation of low-voltage power grid protection.

The invention belongs to the technical field of electric energy quality control, and provides an energy storage type medium-voltage voltage sag and interruption treatment device and a control method thereof.The energy storage type medium-voltage voltage sag and interruption treatment device is arranged between a large power grid and a load in series and comprises a series converter PCS1, a parallel converter PCS2, an energy storage module, an injection type series transformer T1, a parallel transformer T2, a bypass static switch STS and a bypass relay KM1; wherein the injection type series transformer T1 is connected with a large power grid, and the parallel transformer T2 is connected with a load; the series converter PCS1 is connected with the injection type series transformer T1 through the bypass static switch STS and the bypass relay KM1, and compensation voltage is generated in real time through the injection type series transformer T1; the parallel converter PCS2 is respectively connected with the parallel transformer T2 and the common direct current busbar; and the energy storage module is arranged on the common direct current busbar between the series converter PCS1 and the parallel converter PCS2 in parallel.

The invention discloses a multi-line electric energy quality management and power flow transfer device and a control method, the device comprises a first regulation and control module, a second regulation and control module and a shared direct current bus, and the first regulation and control module and the second regulation and control module are of a vertically symmetrical structure; the two regulation and control modules are the same in structure, a primary winding of a three-winding transformer is connected with a medium-voltage alternating-current bus, a wire outlet end of a first secondary winding of the three-winding transformer is connected with a first load through a secondary winding of a first series transformer which is connected in series, and a primary winding of the first series transformer is connected with an alternating-current end of a first three-phase inverter; a wire outlet end of a second secondary winding of the three-winding transformer is connected with an alternating current end of the three-phase rectifier; the medium-voltage alternating-current bus is connected with a second load through a secondary winding of a second series transformer which is connected in series, and a primary winding of the second series transformer is connected with the alternating-current end of the second three-phase inverter. According to the invention, the increasingly complicated power quality requirements under multiple working conditions in the power distribution network facing multi-feeder decoupling regulation and control and mutual assistance are met.

The invention discloses an interconnected transformer area regulation and control method and system based on F-SOP and phase converter cooperation. The method comprises the following steps: S1, acquiring operation parameters of a low-voltage distribution area; s2, calculating the three-phase unbalance degree and the load rate of the output power of the transformer and the voltage of each node of each phase, and judging whether the three-phase unbalance degree and the load rate are in a constraint interval; if the standard is reached, enabling the phase converter and the F-SOP not to act, and returning to S1; if not, starting the phase converter; s3, determining a first optimal action state of the phase converter, and secondarily judging whether the indexes reach the standard or not; if the standard is reached, the phase converter acts according to a first optimal state, otherwise, F-SOP is started; s4, constructing an optimal objective function of the coordinated action economy; and S5, solving the function, determining a second optimal action state of the phase converter and an F-SOP power scheduling instruction, and sending the second optimal action state and the F-SOP power scheduling instruction to the phase converter and the F-SOP. According to the invention, the problem of three-phase imbalance of the transformer in the transformer area and the problem of light and heavy loads are effectively solved, and meanwhile, the problem of three-phase imbalance of the transformer area line is solved.

The invention provides a three-phase unbalanced load adjusting method based on an improved mayfly naiad algorithm, and the method comprises the steps: obtaining and cleaning the voltage and current data of a general meter of a transformer area and all user ammeters in the transformer area, and obtaining the voltage time sequence and current time sequence of the general meter and all user ammeters; based on the voltage time sequence, the phase of each user electric meter is judged through a dynamic time warping algorithm; based on the current time sequence and the phases where the user electricity meters are located, with the minimum three-phase unbalance degree and the minimum number of adjusted user electricity meters as targets, the load of the phases is adjusted by adjusting the positions of the user electricity meters on all the phases through an improved mayfly naiad algorithm, and a final three-phase unbalance load adjusting scheme is obtained through optimization. According to the method, the problem of dependence on manual adjustment experience of the three-phase imbalance condition at present is solved, the three-phase imbalance condition of the transformer area can be adjusted in time, and the labor cost is greatly reduced.

The embodiment of the utility model relates to the electrical field, and discloses a power output switching device and system. The power supply output switching device comprises two three-phase input ends, two three-phase output ends, two single-phase output ends and a switching matrix, the two three-phase input ends are respectively connected with a three-phase power supply; the switching matrix is used for controlling the conduction state of each phase line level circuit between each three-phase input end and the two three-phase output ends and between each three-phase input end and the two single-phase output ends. Therefore, the three-phase power supply directly outputs three-phase power through the three-phase output end, or the three-phase power supply is adjusted to be a single-phase power supply and then single-phase power is output through the single-phase output end. According to the scheme, different line topologies are formed by controlling the conduction of each phase line level line in the switching matrix, different output modes can be realized, the workload of manual wiring is greatly reduced, the test efficiency is improved, the structure is simple, the implementation is easy, and the cost is saved.

The invention provides a control method and system for inter-phase charge state balance of a high-voltage direct-hanging energy storage system. The method comprises the following steps: receiving an active power instruction and a reactive power instruction of the system; measuring the charge state of each battery unit by the system; measuring by the system to obtain a power grid voltage effective value and a power grid current instantaneous value; calculating a power factor of the system according to the active power instruction and the reactive power instruction; calculating active power reference of each phase according to the active power instruction, the reactive power instruction and the charge state of each battery unit; according to the active power instruction, the reactive power instruction, the power grid voltage effective value, the power grid current instantaneous value, the power factor and the active power reference of each phase, calculating to obtain a zero-sequence voltage of the injected three-phase modulation signal; and calculating a three-phase modulation signal after zero-sequence voltage injection according to the zero-sequence voltage. According to the method, the convenience of a control algorithm can be improved, the operation range of inter-phase charge state balance is expanded, and the control efficiency of inter-phase charge state balance is improved.

The invention discloses a grid-connected three-phase unbalanced output control algorithm for alternating-current stable direct-current bus voltage, relates to the technical field of circuits, and aims to solve the technical problems of bus voltage fluctuation and power distribution caused when a three-phase unbalanced load is accessed and an inverter performs three-phase unbalanced output scheduling in the prior art. Comprising the steps of obtaining common connection point power of each phase of an inverter; obtaining a single-phase active power reference value of the inverter according to the power of the common connection point of each phase; the total power reference value of the inverter is calculated according to the single-phase active power reference value of the inverter, and the total active power reference value of the inverter is calculated according to the power reference value of each phase; according to the method, the actual power needing to be compensated for by the inverter is calculated in real time, accurate dispatching and distribution of the power can be achieved, energy loss is reduced, efficiency is improved, the output of the bus voltage control loop is redistributed, the power output of each phase can be matched with the load requirement to the maximum extent, and the overall efficiency of the system is remarkably improved.

The invention discloses a three-phase imbalance phase-change switch switching control system based on a graph neural network, and relates to the technical field of phase-change switch control. In order to solve the problems that in the prior art, deep analysis of load dynamic association and time sequence laws is lacked, so that a control strategy lags behind, switching actions are frequent, the treatment effect is limited, instruction time delay is large, the packet loss rate is high, and accurate synchronization of a commutation moment is difficult to guarantee. According to the method, the accuracy and efficiency of load characteristic analysis are greatly improved by constructing the load association graph structure and identifying the dynamic association mode, the graph neural network is utilized to extract the space-time sequence characteristics of the power grid topology and the load change, and the multi-dimensional and refined optimization of the commutation strategy is realized in combination with the multi-target optimization model, so that the method is suitable for large-scale popularization and application. The Mesh self-organizing network based on the power TD-LTE private network ensures that the instruction can be synchronized in millisecond and accurately sent to the phase-change switch, and provides a solid communication guarantee for effective execution of the strategy.

The invention belongs to the technical field of power grid control, and relates to a transformer area flexible interconnection system three-phase imbalance control method and device and a medium. Taking the transformer area converter controlled by the PQ control algorithm as a target transformer area converter; collecting a first control parameter output by an active power PI controller of the target transformer area converter; based on the upper and lower limits of the voltage target value of the DC bus, performing amplitude limiting setting on the first control parameter of the target transformer area converter to obtain the voltage target value; subtracting the voltage target value from the actual voltage value of the direct-current bus, inputting the difference value into the PI controller, and outputting a second control parameter of the target transformer area converter; taking the second control parameter as a direct-axis current target value, subtracting the direct-axis current target value from a direct-axis current actual value, and taking the difference value as the input of a direct-axis current PI controller; and controlling the target transformer area converter based on the voltage modulation signal output by the PQ control framework. The scheme can effectively improve the power supply reliability of the power distribution area and stabilize the DC bus voltage.

Disclosed in the present invention are an operation and maintenance method and apparatus for severe overload and three-phase imbalance of a distribution transformer, and a medium. The method comprises: by quantifying the degree of difference between devices as the distance between two points, performing clustering analysis on an operation and maintenance state of a distribution transformer, so as to obtain a classification result; and on the basis of a short-term single-phase severe overload category and a short-term three-phase severe overload category in the classification result, establishing a multi-objective optimization model and solving same, so as to obtain a multi-objective optimization result, and on this basis, formulating a day-ahead source-load distribution transformer operation and maintenance plan and performing operation and maintenance control on a distribution network. The present invention provides an operation and maintenance method and apparatus for severe overload and three-phase imbalance of a distribution transformer, and a medium. Solving a multi-objective optimization model to obtain a multi-objective optimization result can ensure that operational risks caused by three-phase imbalance are reduced while balancing three-phase loads, such that differentiated operation and maintenance can be achieved by means of a day-ahead source-load distribution transformer operation and maintenance plan, thereby solving the problem of difficulty in managing severe overload and three-phase imbalance of a distribution transformer to formulate a targeted operation and maintenance plan.

The invention relates to a current-carrying balancing method and device for parallel cables, computer equipment and a storage medium. The method comprises the following steps: acquiring current current data of each cable conductor of parallel cables, and calculating a current error value of each parallel cable based on the current current data of each cable conductor; when the current error value is greater than an error threshold value, generating a control signal of the parallel cables through a control signal generation algorithm based on the current error value of each parallel cable, and identifying a magnetic ring gap adjustment value of the parallel cables based on the control signal; and adjusting the current magnetic ring gap of the parallel cable based on the magnetic ring gap adjustment value to obtain new current data of each cable conductor of the parallel cable, replacing each current current data with each new current data, and returning to execute the above steps until no current error value greater than the error threshold exists. By adopting the method, the current-carrying balance efficiency of the parallel cables can be improved.

The invention discloses a photovoltaic inverter electric energy quality comprehensive control method and system, and the method comprises the steps: obtaining an inverter access point voltage amplitude value, calculating a three-phase voltage mean value and the deviation of each phase voltage, and obtaining an inverter three-phase output active power value; performing three-phase imbalance compensation according to the active power value, and judging whether the three-phase voltage is balanced or not; if the balance is reached, the deviation between the line voltage value after the three-phase imbalance compensation and the upper and lower limit voltage values of the power grid is calculated, the three-phase output reactive power value of the inverter is obtained, and the line voltage is adjusted according to the reactive power value; the method comprises the following steps: adjusting a line voltage, obtaining an inverter access point line load current, calculating a three-phase harmonic current compensation value, carrying out line harmonic current compensation according to the three-phase harmonic current compensation value, and realizing inverter power quality comprehensive control and high-quality power supply based on the adjusted line voltage and the compensated line harmonic current.

The invention relates to the technical field of power monitoring, in particular to a concentrator with an electrical equipment state monitoring function. Obtaining an unbalance degree according to the state characteristic values among the three phases; clustering is carried out according to the unbalance degree of all historical moments, and distribution intensity is obtained according to interval characteristics of different moments in a moment cluster; obtaining a data similarity according to the unbalance degree in the time cluster; obtaining reference credibility according to the moment quantity characteristics, the distribution intensity and the data similarity in the moment cluster; according to the difference characteristic of the unbalance degree corresponding to the current moment and the reference moment cluster and the reference credibility of the reference moment cluster, obtaining the abnormity degree; and obtaining an anomaly trend value according to the anomaly degree of the adjacent historical time period of the current moment. The early warning index of the current moment is obtained according to the abnormity degree and the abnormity trend value, and early warning is carried out, so that the monitoring accuracy of the concentrator on the power utilization state of the electrical equipment is improved.

The disclosure relates to a power electronics device having at least two inverters and a transformer apparatus having a core arrangement, at least one primary winding and at least one secondary winding that wind around the core arrangement at least in sections.

The invention discloses an unbalanced load compensation method for a three-phase four-wire three-level converter. According to the method, a three-phase four-wire system three-level converter bridge arm voltage mathematical model is established based on sine carrier in-phase laminated modulation, and harmonic content analysis is completed; an SOGI-pro module is established (an error integration link is added at the input front end of a D axis of an SOGI filter, and D and Q axis second-order band-pass filters are transformed into third-order band-pass filters), so that the positive and negative sequence separation precision of three-phase unbalanced load voltage is improved. According to the method, the order of the SOGI filter is improved by reasonably designing a closed-loop transfer function, and the filtering effect of the SOGI filter in high and low frequency bands is enhanced. And a sequence-dividing imbalance compensation control loop is designed based on the three-sequence dq0 coordinate system, so that zero-static-error tracking of a positive-sequence fundamental component and powerful suppression of negative-sequence and zero-sequence imbalance components are realized. According to the invention, the accuracy of traditional positive and negative sequence separation is improved, so that the unbalanced load compensation effect under sequence separation control can be improved.

The invention discloses a three-phase unbalanced power flow line loss analysis method, which comprises the following steps of: establishing a power flow model of a three-phase unbalanced system based on a sequence component method; the power flow model comprises admittance matrixes respectively corresponding to a positive sequence, a negative sequence and a zero sequence, and equivalent admittance corresponding to any two of the positive sequence, the negative sequence and the zero sequence; converting the power flow model, and determining a first relational expression among the coupled positive sequence current, the equivalent admittance and the uncoupled positive sequence current, and a second relational expression among the coupled negative sequence current, the equivalent admittance and the uncoupled negative sequence current; determining a positive sequence electrical component according to the first relational expression, and determining a negative sequence electrical component according to the second relational expression; and determining the line loss of the three-phase unbalanced system according to the positive sequence electrical component and the negative sequence electrical component. According to the method provided by the invention, the accuracy of line loss analysis can be improved.

The invention discloses a line loss reduction method and device based on three-phase load adjustment, equipment and a medium, and the method comprises the steps: collecting a three-phase load current corresponding to a power transmission line in response to a loss reduction request, and constructing a load square-time curve; creating a line loss change objective function according to a load square-time curve; calculating the minimum value of the line loss change objective function under the load constraint, and determining an adjustment load; and adjusting the three-phase load current according to the adjustment load to reduce the line loss of the power transmission line. Therefore, line loss calculation can be accurately carried out for continuous and changing three-phase load current, and the accuracy of line loss management and control is effectively improved.

Disclosed embodiments provide methods, systems, and computer program products for implementing enhanced phase power load balancing of a set of systems (e.g., the set of systems of a data center) using a subset of the systems. Disclosed embodiments extract phase currents of a three-phase power source of the set of systems, and determine, based on extracted phase currents for the set of systems, input phase power load balancing for the subset of the systems. Disclosed embodiments alter the current input phase power balancing of the subset, unbalancing the input phase power load for the subset of the systems to provide enhanced phase power load balancing of the set of systems. Altering the current input phase power balancing for the subset of the systems can be implemented by power shifting between power supply units (PSUs), phase rotations, or input phase switching of power distribution unit (PDU) switchable output ports.